Marking apparatus using magnetism

ABSTRACT

Provided is an apparatus for marking a metal using magnetism. The apparatus includes an upper body having an elastic unit insertion groove in which an elastic unit is inserted, an operation body through which a cylindrical part having a diameter less than that of the elastic unit insertion groove vertically passes, the operation body being coupled to a lower portion of the upper body, wherein an electromagnetic coil is disposed around the cylindrical part, a lower body through which an induction part having a diameter less than that of the cylindrical part vertically passes, the lower body being coupled to a lower portion of the operation body, a control part connected to the electromagnetic coil to control an electromotive force of the electromagnetic coil, a plunger including a head part inserted into the elastic unit insertion groove, a stamping rod inserted into the cylindrical part, and a stamping pin inserted into the induction part, and an elastic unit coupled to the stamping rod and inserted into the elastic unit insertion groove to elastically support the plunger.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for marking a metal, and more particularly, to a metal marking apparatus in which a plunger for marking a surface of a metal vertically reciprocates using magnetism to improve a stamping force and a life of the apparatus even through the plunger is reduced in thickness.

2. Description of the Related Art

In general, proper serial numbers that indicate a manufacturing date, a manufacturer, etc., are marked to effectively manage corresponding parts in chassis and parts of a vehicle, main parts of an airplane, and the like.

Such a marking apparatus, as shown in FIGS. 7 and 8, is disclosed in Korean Publication Patent No. 2001-0067566 filed by the same applicant. According to the marking apparatus, two solenoid valves 140 and 150 are alternately opened and closed to supply pressure air to an air tube 202 of a stamping part 170 through a pressure air intake part 130, thereby allowing the pressure air to fill a pressure chamber 212 and also allowing a piston 222 to get forward.

The advancing piston 222 marks an object 300 using a stamping pin 242 and returns by an elastic force of a return spring 230. The compressed air advancing the piston 222 is exhausted through exhaust parts 145 and 155 by the returning piston 222.

However, in such the air pressure marking apparatus, a great exhaust noise (above 80 db) may be generated by the air pressure. Also, since a compressor that is a separate air generation device is required, a structure of the marking apparatus is complicated and a manufacturing cost is expensive. In addition, the marking apparatus breaks down easily.

Thus, to overcome the above-described limitations of the related art air pressure marking apparatus, a marking apparatus using magnetism is being developed. A structure of the marking apparatus using the magnetism will be described.

FIG. 9 is a sectional view of a related art magnetic marking apparatus, and FIG. 10 is a view of a state in which a plunger of a related art magnetic marking apparatus marks a metal while descending.

An operation body 310 is coupled to a lower portion of an upper cover 300. A lower body is coupled to a lower portion of the operation body 310, and a plunger 330 is coupled to the inside of the operation body 310. Thus, the plunger 330 is elastically supported by an elastic unit 340.

A vertically penetrated cylindrical part 311 is disposed at a center of the operation body 310. An electromagnetic coil 312 is disposed outside the cylindrical part 311, and a control part 313 for controlling the electromagnetic coil 312 is separately disposed and connected to the electromagnetic coil 312.

An induction part 321 vertically passes through the lower body 320. A sleeve 322 for straightly inducing a stamping pin is disposed outside the induction part 321. An electric unit insertion groove 323 having a width greater than that of the induction part 321 is defined in an upper portion of the induction part 321.

The plunger 330 includes a head part 331, a stamping rod 332, and a stamping pin 333. The head part 331 is formed of a pure iron (Fe) to achieve maximum efficiency by the magnetism. The stamping rod 332 is formed of cemented carbide material to endure an impact colliding with the lower body 320. Also, the stamping pin 333 has a thin and long shape to easily mark the metal M. The plunger 330 is coupled to and supported by the elastic unit 340 inserted into the elastic unit insertion groove 323.

Thus, in the marking apparatus including the above-described components, when the current is applied to the electromagnetic coil 312 by the control part 313, an electromotive force is generated to descend the plunger 330. As a result, the metal M is marked by the stamping pin 333 of the descending plunger 330.

Since the stamping rod 332 of the descending plunger 330 compresses the elastic unit 340 and a bottom surface of the stamping rod 332 has an angle of about 180° equal to a horizontal line, the stamping rod 332 strongly collides with the lower body 320 and thus does not descend any longer.

Then, when the electromotive force is removed, the plunger 333 ascends by the elastic unit 340 to return its original position.

However, in the related art marking apparatus, when the stamping rod 332 collides with the lower body 320 while descending, the stamping rod 332 and a top surface of the lower body 320 are horizontal)(180° to each other. As a result, a frictional force increases and a stroke is shorter, and thus, an efficient stamping force is not generated.

Thus, the plunger 330 has a wide width to increase a load, thereby improving the electromotive force. As a result, the overall outer size of the marking apparatus increases to increase manufacturing costs. In addition, the stamping speed is reduced to reduce the marking speed.

Also, since the stroke is reduced, it may be difficult to mark an uneven surface or a curved surface.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a marking apparatus that improves a related art inefficient stroke to improve a stamping speed and a marking speed, thereby improving a stamping force.

Another object of the present invention is to provide a marking apparatus that reduces the overall outer size to reduce manufacturing costs and improves a stamping force than that of a related art marking apparatus to improve its life.

According to an aspect of the present invention, there is provided an apparatus for marking a metal using magnetism, the apparatus including: an upper body having an elastic unit insertion groove in which an elastic unit is inserted; an operation body through which a cylindrical part having a diameter less than that of the elastic unit insertion groove vertically passes, the operation body being coupled to a lower portion of the upper body, wherein an electromagnetic coil is disposed around the cylindrical part; a lower body through which an induction part having a diameter less than that of the cylindrical part vertically passes, the lower body being coupled to a lower portion of the operation body; a control part connected to the electromagnetic coil of the operation body to control an electromotive force of the electromagnetic coil; a plunger including an upper head part inserted into the elastic unit insertion groove of the upper body, a middle stamping rod inserted into the cylindrical part of the operation body, and a lower stamping pin inserted into the induction part of the lower body; and an elastic unit coupled to the stamping rod of the plunger and inserted into the elastic unit insertion groove of the upper body to elastically support the plunger.

A tapered part having a gradually decreasing diameter may be disposed on a lower end of the cylindrical part of the operation body, and a tapered part having a shape corresponding to that of the lower end of the cylindrical part including the tapered part may be disposed on a lower end of the stamping rod of the plunger.

An angle between the cylindrical part of the operation body and the tapered part of the stamping rod of the plunger may be about 30°.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is an exploded perspective view illustrating a partial section of a marking apparatus according to an embodiment of the present invention;

FIG. 2 is an enlarged sectional view illustrating an operation body of a marking apparatus according to an embodiment of the present invention;

FIG. 3 is a graph illustrating a variation of suction force according to angle and configuration of plunger (movable core);

FIG. 4 is an enlarged view illustrating a plunger of a marking apparatus according to an embodiment of the present invention;

FIG. 5 is an assembled sectional view of a marking apparatus according to an embodiment of the present invention;.

FIG. 6 is a view of a state in which a plunger marks a metal using magnetism while the plunger descends by an electromotive force of control part in FIG. 5;

FIG. 7 is a block diagram of a related art pneumatic marking apparatus;

FIG. 8 is a sectional view of a related art pneumatic marking apparatus;

FIG. 9 is a sectional view of a related art magnetic marking apparatus; and

FIG. 10 is a view of a state in which a plunger of a related art magnetic marking apparatus marks a metal while descending.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 1 is an exploded perspective view illustrating a partial section of a marking apparatus according to an embodiment of the present invention.

A marking apparatus D according to the present invention includes an upper body 10, an operation body 20, a lower body 40, a plunger 50, and an elastic unit 60.

A downwardly opened elastic unit insertion groove 11 is defined with a predetermined depth in the upper body 10. A sleeve 11 a for straightly inducing a stamping rod 52 may be further disposed at an inlet side of the elastic unit insertion groove 11.

FIG. 2 is an enlarged sectional view illustrating an operation body of a marking apparatus according to an embodiment of the present invention.

A vertically penetrated cylindrical part 21 is disposed at a center of the operation body 20. The cylindrical part 21 has a diameter less than that of the elastic unit insertion groove 11 defined in the upper body 10. This is done for reasons that a head part 51 (that will be described below) of the plunger 50 and the elastic unit 60 are hooked on the cylindrical part 21, but are inserted into the cylindrical part 21.

A tapered part 22 having a gradually decreasing diameter is disposed at a lower end of the cylindrical part 21. An angle between both tapered surfaces of the tapered part 22 may be about 30°. An electromagnetic coil 23 is disposed outside the cylindrical part 21. A control part 30 is connected to the electromagnetic coil 23.

FIG. 3 is a graph illustrating a variation of a suction force (marking force) according to an angle and configuration of a plunger (movable core) of a solenoid valve.

This graph is disclosed on a web-page with the http://www.solenoid.co.kr/tech/tech4.htm.

According to the graph shown in FIG. 3, when the plunger has an angle of about 30°, it is seen that a stroke increases even through any large force is not applied.

Thus, when a strong stamping force is applied to mark a metal M, an angle between both tapered surfaces of the tapered part 22 was about 30° in consideration of deformation and wear of the plunger.

The lower body 40 includes an induction part 41 having a diameter less than that of the cylindrical part 21 of the operation body 20 and vertically passing therethrough. A sleeve for straightly inducing a stamping pin 53 may be disposed outside the induction part 41.

FIG. 4 is an enlarged view illustrating a plunger of a marking apparatus according to an embodiment of the present invention.

The plunger 50 has a predetermined length and includes the head part 51, the stamping rod 52, and the stamping pin 53.

The head part 51 has a diameter insertable into the elastic unit insertion groove 11 of the upper body 10. Since the stamping rod 52 has a diameter closely insertable into the cylindrical part 21 of the operation body 20, the stamping rod 52 has a diameter less than that of the head part 51. The stamping pin 53 is disposed at a lower portion of the stamping rod 52 and has a thin and long shape. Also, the stamping pin 53 has a diameter insertable into the induction part 41.

In particular, a tapered part 54 corresponding to the tapered part 22 disposed on the cylindrical part 21 of the operation body 20 is disposed at a lower end of the middle stamping rod 52 of the plunger 50. An angle between both tapered surfaces of the tapered part 54 may be about 30°.

That is, since the plunger 50 includes the tapered part 54 having a cone shape than a simple flat shape having a planar bottom surface, the plunger 50 may be slim in configuration.

In spite of the slim plunger 50, as shown in the graph, the plunger 50 has a suction force (stamping force) approximately three times or more greater than that of a related art plat type plunger. Also, since the overall plunger is formed of cemented carbide, a life of the plunger 50 may be improved by more than ten times.

The elastic unit 60 is wound around and coupled to the middle portion of the stamping rod 52 of the plunger 50. The elastic unit 60 is inserted into the elastic unit insertion groove 11 of the upper body 11 and then coupled in a hung state between a lower end of the head part 51 and an upper end of the operation body 20.

FIG. 5 is an assembled sectional view of a marking apparatus according to an embodiment of the present invention.

The operation body 20 is fixedly coupled to an upper side of the lower body 40. A side of the stamping pin 53 of the plunger 50 is inserted into and coupled to the cylindrical part 21 of the operation body 20. Here, the elastic unit 60 is fitted into and coupled to the stamping rod 52 of the plunger 50. The stamping rod 52 is induced by the sleeve 11 a disposed at the inlet side of the elastic unit insertion groove 11 to straightly induce the stamping rod 52 while moving through the cylindrical part 21. As a result, the stamping rod 52 has straightness.

When the tapered part 54 of the plunger 50 does not descend any longer by the tapered part 22 disposed on the cylindrical part 21 of the operation body 20, the upper body 10 is fixedly coupled to an upper portion of the operation body 20. Here, the head part 51 of the plunger 50 and the elastic unit 60 are inserted into and coupled to the elastic unit insertion groove 11 of the upper body 10.

Although not shown, the marking apparatus D may be fixedly coupled to mark desired characters while moving along an X-axis and Y-axis by a transfer motor.

Hereinafter, an operation of the marking apparatus including the above-described components will be described.

FIG. 6 is a view of a state in which a plunger marks a metal using magnetism while the plunger descends by an electromotive force of control part in FIG. 5.

When the control part 30 applies 24 volts DC current having a variable frequency from about 1 Hz to about 40 Hz, the plunger 50 momentarily strongly descends about one time to about forty times per second by an electromotive force of the electromagnetic coil 23 to allow the stamping pin 53 to mark the metal M.

Here, the stamping pin 53 is inducted by the sleeve 42 disposed outside the induction part 41 to induce straightly induce the stamping pin 53 while the plunger 50 descends to allow the stamping pin 53 having a thin and long length to move through the induction part 41 of the lower body 40. As a result, the stamping pin 53 has straightness.

Also, when the plunger 50 descends by the momentary electromotive force, since the stamping rod 52 has the cone shape, the electromotive force between the tapered part 54 of the stamping rod 52 and the tapered part 22 of the operation body 20 increases to improve a stamping force when compared to the related art marking apparatus.

The head part 51 of the plunger 50 descending by a signal transmitted from the control part 30 descends to compress the elastic unit 60. The plunger 50 completely performing the marking process ascends by an elastic force of the elastic unit 60 to return to its original position.

According to the present invention, the plunger 50 descends by one control part 30 and ascends by the elastic unit 60. Thus, a quick operation may be performed, and also the stamping force may be optimized to perform a high speed marking process.

Therefore, the plunger has the diameter less than that of the related art plunger to minimize a frictional force and improve the stamping force by approximately three times or more. Also, the stroke increases to improve the stamping force. In addition, it may be possible to mark the uneven surface or the curved surface, and the marking speed is improved to realize a very efficient marking apparatus.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. An apparatus for marking a metal using magnetism, the apparatus comprising: an upper body having an elastic unit insertion groove in which an elastic unit is inserted; an operation body through which a cylindrical part having a diameter less than that of the elastic unit insertion groove vertically passes, the operation body being coupled to a lower portion of the upper body, wherein an electromagnetic coil is disposed around the cylindrical part; a lower body through which an induction part having a diameter less than that of the cylindrical part vertically passes, the lower body being coupled to a lower portion of the operation body; a control part connected to the electromagnetic coil of the operation body to control an electromotive force of the electromagnetic coil; a plunger comprising an upper head part inserted into the elastic unit insertion groove of the upper body, a middle stamping rod inserted into the cylindrical part of the operation body, and a lower stamping pin inserted into the induction part of the lower body; and an elastic unit coupled to the stamping rod of the plunger and inserted into the elastic unit insertion groove of the upper body to elastically support the plunger.
 2. The apparatus of claim 1, wherein a tapered part having a gradually decreasing diameter is disposed on a lower end of the cylindrical part of the operation body, and a tapered part having a shape corresponding to that of the lower end of the cylindrical part comprising the tapered part is disposed on a lower end of the stamping rod of the plunger.
 3. The apparatus of claim 2, wherein an angle between the cylindrical part of the operation body and the tapered part of the stamping rod of the plunger is about 30°. 